A column-oriented database is a database that stores data by using a column-related storage architecture. Data in each column is serialized and stored independently, and data in a row spreads across different columns and is separately stored in different data areas.
The column-oriented database has two storage areas: a row area and a column area. Original data is stored in the column area; and new data generated by a data manipulation language (DML) transaction operation is stored in the row area. Although data is organized by column, rows of data may be actually required to be in consistent format. Therefore, when a data modification is made, modifications to different columns are involved, and in this process, Atomicity, Consistency, Isolation, Durability (ACID) attributes that guarantee that database transactions are processed concurrently and need to be guaranteed in the row area.
Query efficiency in the column-oriented database is often reduced using such databases, especially when a capacity of a database is large.